Possibly a nod to his well-received three-round tilt with Demian Maia (Pictures) at UFC 87 on Aug. 9, Jason MacDonald (Pictures) will be back in action sooner rather than later. The Red Deer, Alberta resident will replace an injured Jason Day (Pictures) against Jason Lambert (Pictures) at UFC 88 “Breakthrough” on Sept. 6 at the Philips Arena in Atlanta.

The bout will mark Lambert’s debut at middleweight, who spent the entirety of his seven-year career toiling in the 205-pound ranks. After reeling off a trio of Octagon wins in 2006, Lambert (23-8) has dropped his last three out of four, necessitating a change of pace for the Carlsbad, Calif. resident.

The well-rounded Lambert holds a key knockout victory over Renato “Babalu” Sobral at UFC 68 “Uprising” in March 2007, where the father of one came back from deficit to overcome the regarded Brazilian.

Like Lambert, MacDonald got off to a brisk start in the UFC with a pair of slick submission victories, but fell to former divisional champion Rich Franklin (Pictures) at UFC 68. MacDonald has flipped between wins and losses ever since, but his gutsy Aug. 9 performance against Brazilian jiu-jitsu black belt Maia was considered a highlight of UFC 87’s card.